Effects of ericoid mycorrhizal fungi on performance of V. macrocarpon and V. oxycoccos under abiotic stresses related to climate change

View the project final report

Commodities

• Fruits: berries (cranberries)

Practices

• Crop Production: biological inoculants, nutrient cycling

This study, “Effects of ericoid mycorrhizal fungi on performance of V. macrocarpon and V. oxycoccos under abiotic stresses related to climate change,” endeavors not only to encourage sustainable agricultural practices but to expand stress tolerance of cranberry crops, thereby easing challenges faced by growers. Cranberry (Vaccinium macrocarpon Ait.) growers are under increasing pressure as a result of climate change, which is affecting cranberry production through repeated cycles of water and heat stress. These climatic events are well-established and predicted to intensify. Cranberry vines have evolved in a unique ecosystem (bog) and are highly susceptible to water and heat stress. Hoping to ameliorate the effects of these abiotic stressors and reduce the negative effects on yield and fruit size, growers tend to over-fertilize and irrigate vines. However, these practices have widely-documented negative impacts on water quality of the surrounding wetlands with no benefit on fruit production. Multiple studies conducted in blueberry have shown that inoculation with ericoid mycorrhizal fungi (ErMF) have a reductive effect of abiotic stressors, improving plant vigor. ErMF are ubiquitous, with local strains already present and active in agricultural soils, such as the cranberry production system. The application of non-native ErMF may stretch cranberry’s range of tolerance, allowing growers to lessen water and fertilizer usage in response to climate change impacts. The main objective of this study is to evaluate the impact of ericoid mycorrhizal fungi (ErMF) Rhizoscyphus ericae strains on cranberry vine performance under four abiotic stressors: (1) soil moisture, (2) temperature, (3) pH, and (4) nutrient deficiency.

Plant sets in each condition will be inoculated with different mycorrhizal fungal strains. Colonization will be verified after a six-week incubation period. Once confirmed, we will subject ErMF (+) and (-) plants to adverse growing conditions. Throughout the exposure period, we will record rates of photosynthesis and collect plant material to measure levels of the stress hormones, record plant water potential, dry weight of above and below ground biomass. Project outcomes will include increased researcher understanding of how different strains of ErMF affect vine performance in cranberry and evaluation through the presentation of findings. Growers will be surveyed before and after presentations to gauge their knowledge of the direct and indirect impacts of ErMF on crops and the environment; we expect to significantly increase grower interest in this new tool for sustainability, particularly given concrete benefits for growers and the environment, lowering requisite water and fertilizer usage. 

The expected learning outcomes for this research are as follows: 1) researchers will learn how different strains of ErMF affect vine performance via physiological measurements (including stress hormone levels, photosynthesis rates, biomass, and water potential) in V. macrocarpon and V. oxycoccus across different abiotic stressors; 2) researchers will combine different successful strains with microbiome samples from marsh beds to more effectively manage plant stress response; 3) 30% of growers surveyed will have increased knowledge of how ErMF impacts cranberry and environmental health. This project will expand the limited body of knowledge on ericoid mycorrhizae and lead to new avenues of research on this topic. If this project is successful, it could lead to the production of a commercial inoculum tailored to specific growing regions. We hope to provide growers with the opportunity to employ a new tool that can combat inevitable environmental changes. The expected action outcomes are that: 1) growers will begin applying ErMF for bed management; 2) growers will decrease usage of water and fertilizer applications, resulting in improved plant vigor and reduced environmental impact from fertilizers.